排序方式: 共有14条查询结果,搜索用时 328 毫秒
1.
Heikki Kallio Saska Tuomasjukka Anu Johansson Raija Tahvonen Niina Nieminen Olli Sjvall Juha‐Pekka Kurvinen Hanna Kivini 《European Journal of Lipid Science and Technology》2005,107(2):101-106
Currant oils have special health properties due to their moderate contents of α‐linolenic, γ‐linolenic and stearidonic acids. The distribution of fatty acids (FA) in the triacylglycerols (TAG) may affect the beneficial effects. Seed oils of wild northern red currant (NRC) (Ribes spicatum L.) from Northern Finland and of wild alpine currant (AC) (R. alpinum L.) from the South‐West coast of Finland were investigated. The purified TAG were analysed by tandem mass spectrometry by applying the ammonia negative ion chemical ionisation – collision‐induced dissociation method. Molecular weight fractions rich in C18:3 FA and C18:4 FA were investigated. Of the total oil, the molecular weight species 54:7 (ACN:DB), 54:8 and 54:9 were more abundant in NRC than in AC, being 21.0%, 15.8%, 7.4% and 16.2%, 11.2%, 4.8%, respectively (p <0.05). The species 52:6 was more abundant in AC (3.1%) than in NRC (2.6%) (p <0.05). The preferential order of FA to be in the sn‐2 position in both berries was typically C18:1 > C18:2 > C18:4 > C18:3. No difference was observed between relative locations of C16:0 FA and C18:3 FA in either of the oils. Within the TAG consisting of FA combinations C18:3/C18:3/C18:1 (54:7), C18:1 was more preferentially in the sn‐2 position (p <0.05) in AC (93.2%) than in NRC (74.6%), and in the case of C18:3, the preference was vice versa. Within the molecular weight species 54:9, FA combination C18:4/C18:3/C18:2, linoleic acid preferentially occupied the secondary position (p <0.005) in both berries, and the proportion of the TAG regioisomer pair sn‐C18:3‐C18:4‐C18:2 + sn‐C18:2‐C18:4‐C18:3 was more abundant (30.2%) in NRC than in AC (15.3%). Within the TAG species 52:6, proportions of all the existing combinations, C16:0/C18:3/C18:3, C16:0/C18:4/C18:2 and C16:1/C18:3/C18:2, varied between the two berry species (p <0.005). 相似文献
2.
Quantitation of acyl migration during lipase-catalyzed acidolysis, and of the regioisomers of structured triacylglycerols formed 总被引:1,自引:0,他引:1
Huiling Mu Juha-Pekka Kurvinen Heikki Kallio Xuebing Xu Carl-Erik Høy 《Journal of the American Oil Chemists' Society》2001,78(9):959-964
Various MLM-type (M, medium-chain fatty acids; L, long-chain fatty acids) structured triacylglycerols were produced in pilot-
or small-scale packed-bed reactors by lipasecatalyzed acidolysis. The incorporation and acyl migration of octanoic acid were
measured by gas chromatography and Grignard degradation, and ranged from 39.0 to 48.7% and 0.6 to 9.3%, respectively. Quantitation
of triacylglycerol molecular species was performed by ammonia negative ion chemical ionization (NICI) mass spectrometry (MS).
The proportion of ACN (acyl carbon number) 34 species that contained one C18 fatty acid and two C8∶0′ in samples analyzed, varied from 12.5 to 23.2%. The selected regioisomers MLM and MML within the ACN 34 species group were
quantified by NICI tandem MS (MS/MS) and were in the range of 97.1 to 98.4% and 1.6 to 2.9%, respectively. There was no correlation
between the level of acyl migration during lipase-catalyzed esterification and the level of regioisomers of the selected MLM-type
triacylglycerols in the structured lipid samples. 相似文献
3.
J. -P. Kurvinen O. Sjövall H. Kallio 《Journal of the American Oil Chemists' Society》2002,79(1):13-22
Triacylglycerol (TAG) molecular weight distribution and regioisomeric structure of selected molecular weight species in human
milk and in 32 human milk substitutes was determined. Negative ion chemical ionization mass spectrometry was used to determine
the molecular weight distribution and collisionally induced dissociation tandem mass spectrometry applied to identify the
sn-2 and sn-1/3 positions of fatty acids in TAG. The main molecular weight species of human milk TAG in decreasing order of abundance
were 52∶2, 52∶3, 52∶1, 54∶3, 50∶2, 50∶1, 54∶4, 48∶1, 54∶2, 48∶2, 46∶1, 52∶4, and 50∶3 (acyl carbon number/number of double
bonds), constituting 83 mol% of total TAG molecular species. In human milk substitutes, the proportion of the corresponding
molecular weight species varied from 33 to 87 mol%. The main TAG regioisomers within the molecular weight species 52∶2, 52∶3,
and 50∶1 in human milk were 18∶1-16∶0-18∶1 (83 mol%), 18∶1-16∶0-18∶2 (83 mol%), and 18∶1-16∶0-16∶0 (80 mol%), respectively.
In human milk substitutes, the corresponding proportions varied in a wide range of 0–82 mol%, 0–100 mol%, and 0–73 mol%, respectively.
Although TAG structures in some human milk substitutes closely resembled those in human milk, the great variation among samples
leads to the conclusion that it is still possible to improve the TAG composition in human milk substitutes by applying novel
methods to synthesize structured TAG. 相似文献
4.
Alterations in chylomicron and VLDL TAG and the magnitude of postprandial lipemia were studied in healthy volunteers after
two meals of equal FA composition but different TAG-FA positional distribution. Molecular level information of individual
lipoprotein TAG regioisomers was obtained with a tandem MS method. The incremental area under the response curve of VLDL TAG
was large (P=0.021) after modified lard than after lard. In plasma TAG, the difference did not quite reach statistical significance (P=0.086). In general, there were less TAG with palmitic acid in the sn-2 position and more TAG with oleic acid in the sn-2 position in chylomicrons than in fat ingested. From 1.5 to 8 h postprandially, the proportion of individual chylomicron
TAG was constant or influenced by TAG M.W. VLDL TAG regioisomerism was similar regardless of the positional distribution of
fat ingested. Significant alterations were seen in VLDL TAG FA, in M.W. fractions, and in individual regioisomers with respect
to time. The TAG sn-14∶0-18∶1-18∶1+sn-18∶1-18∶1-14∶0, sn-16∶0-16∶1-18∶1+sn-18∶1-16∶1-16∶0, and sn-16∶1-18∶1-18∶1+sn-18∶1-18∶1-16∶1 decreased (P<0.05); and sn-16∶0-16∶0-18∶2+sn-18∶2-16∶0-16∶0, sn-16∶0-16∶0-18∶1+sn-18∶1-16∶0-16∶0, sn-16∶0-18∶1-16∶0, and sn-16∶0-18∶1-18∶2+sn-18∶2-18∶1-16∶0 increased (P<0.05) after both meals. In conclusion, positional distribution of TAG FA was found to affect postprandial lipid metabolism
in healthy normolipidemic subjects. 相似文献
5.
Probiotics are commonly included in dairy products. These products require cold storage and transportation, which limits their use. Here, we describe the inclusion of the probiotic strain Bifidobacterium lactis Bb-12 in a dry food matrix, an oat-based cereal bar, and its detection in faeces after consumption of this product. One week after cessation of B. lactis Bb-12 feeding, it could be identified in the faeces of five of the nine subjects. 相似文献
6.
We prepared model Schiff bases from 2-[9-oxo]nonanoyl glycerol (2-MAG-ALD) and various amino compounds. 2-MAG-ALD was obtained
by pancreatic lipase hydrolysis of trioleoyl glycerol and reductive ozonolysis of the resulting 2-monooleoyl glycerol. The
reaction products were purified by thin-layer chromatography. Schiff bases were synthesized in greater than 50% yield by reacting
2-MAG-ALD with twofold molar excess of valine, Nα-acetyl-l-lysine methyl ester and the tripeptides glycyl-glycyl-glycine, glycyl-glycyl-histidine, and glycyl-histidyl-lysine in aqueous
methanol and with 1-palmitoyl-2-stearoyl glycerophosphoethanolamine (PE) in chloroform.methanol for 16 h at room temperature.
Prior to analysis the bases were reduced with sodium cyanoborohydride in methanol for 30 min at 4°C. Reaction products were
analyzed by high-performance liquid chromatography/electrospray ionization/mass spectrometry (HPLC/ESI/MS). Reduced Schiff
bases of 2-MAG-ALD with PF and amino acids were analyzed by normal-phase HPLC/ESI/MS and those with peptides by reversed-phase
HPLC/ESI/MS. Single adducts were obtained in all cases and both the α-amino group of valine and the ε-amino group of Nα-acetyl-l-lysine methyl ester were reactive. Molecular ions of reaction products were the only detected ions in the negative ionization
mode, whereas in the positive ion mode sodiated molecular ions were also detected. The present study suggests that 2-MAG-ALD
may form Schiff base adducts with amino compounds in other aqueous media, such as the intestinal lumen and in the hydrophobic
environment of cell membranes. 相似文献
7.
The effect of low α-linolenic acid diet on glycerophospholipid molecular species in guinea pig brain
The changes in guinea pig brain (cerebrum) glycerophospholipid molecular species resulting from a low α-linolenic acid (ALA)
diet are described. Two groups of six guinea pigs were raised from birth to 16 wk of age on either an n-3 deficient diet containing
0.01 g ALA/100 g diet or n-3 sufficient diet containing 0.71 g AlA/100 g diet. Molecular species of diradyl glycerophosphoethanolamine.
(GroPEtn), glycerophosphocholine, glycerophosphoserine, and glycerophosphoinositol were analyzed by high-performance liquid
chromatography with on-line electrospray ionization mass spectrometry (HPLC/ESI/MS). Alkenylacyl GroPEtn species were determined
by comparing spectra before and after mild acid treatment while diacyl- and alkylacyl species were distinguished by HPLC/
ESI/MS. The proportions of phospholipid classes and of the diradyl GroPEtn subclasses were not altered by diet changes. The
main polyunsaturated molecular species of diradyl GroPEtn subclasses and of phosphatidylcholine and phosphatidylserine (PtdSer)
contained 16∶0, 18∶0, or 18∶1 in combination with docosahexaenoic acid (DHA, 22∶6n-3), docosapentaenoic (DPA, 22∶5n-6), or
arachidonic acid (ARA, 20∶4n-6). A significant proportion of DPA containing species were present in both diet groups, but
in n-3 fatty acid deficiency, the proportion of DPA increased and DHA was primarily replaced by DPA. The combined value of
main DHA and DPA containing species in the n-3 deficient group ranged from 91-111% when compared with the n-3 sufficient group,
indicating a nearly quantitative replacement. The n-3 fatty acid deficiency did not lower the content of ARA containing molecular
species of PtdSer of the guinea pig brain as reported previously for the rat brain. The molecular species of phosphatidylinositol
were not altered by n-3 fatty acid deficiency. The present data show that the main consequence of a low ALA diet is the preferential
replacement of DHA-containing molecular species by DPA-containing molecular species in alkenylacyl- and diacyl GroPEtn and
PtdSer of guinea pig brain. 相似文献
8.
Oxidized lipoproteins have a recognized role in atherogenesis, but molecular-level research on oxidized lipids in lipoproteins
and the effect of diet on these molecules have been limited. In the present study, the effects of three sunflower seed oil
diets differing in oxidation levels (PV in oils 1, 84, and 223 mequiv O2/kg) on lipoprotein lipid oxidation in growing pigs were investigated. The emphasis was on the investigation of oxidized TAG
molecules found in chylomicrons and VLDL. A method based on RP-HPLC and electrospray ionization-MS was used for the analysis
of oxidized TAG molecules. The baseline diene conjugation method was used for the estimation of in vivo levels of lipoprotein lipid oxidation. Several oxidized TAG structures were found in the samples. These products consisted
of TAG molecules with a hydroxy, an epoxy, or a keto group attached to a FA, and of TAG molecules containing an aldehyde structure
derived from a FA. The lipoprotein lipids and TAG were more oxidized in the pigs fed on the most oxidized oil compared with
those fed on nonoxidized oil. Oxidation of dietary fat was reflected in the lipoprotein oxidation. New, detailed information
on oxidized TAG molecules of chylomicrons and VLDL was obtained. 相似文献
9.
Antti Oulasvirta Esko Lehtonen Esko Kurvinen Mika Raento 《Personal and Ubiquitous Computing》2010,14(3):237-249
Microblogging is a “Mobile Web 2.0” service category that enables brief blog-like postings from mobile terminals and PCs to
the World Wide Web. To shed light on microblogging as a communication genre, we report on multiple analyses of data from the
first 10 months of a service called Jaiku. The main finding is that microblogging centers on selective, I-centered disclosure
of current activities and experiences, making daily experiences visible for others. The high frequency of brief and mundane status updates,
like “working,” may be a second-order effect resulting from posting becoming a routine executed to keep the audience interested.
The results highlight the importance of reciprocal activity and feedback in users’ motivation to invest in this activity. 相似文献
10.
Antti?OulasvirtaEmail author Esko?Kurvinen Tomi?Kankainen 《Personal and Ubiquitous Computing》2003,7(2):125-134
A thorough appreciation of physical, social, interactional, and psychological contextual factors is crucial in the design of ubiquitous computing applications. This paper investigates the benefits of a method called bodystorming for carrying out design sessions in the original context, `in the wild', instead of the office. A location is selected that is identical or similar to the original environment. Innovation, carried out on-site, is based on ethnographical data presented as concrete design questions. Individual solutions to design questions are brainstormed and discussed on-site. Facets of data collection and preparation, formulation of design questions, selection of locations, session administration, and evaluation of design ideas are presented. We found that bodystorming permits immediate feedback for generated design ideas, and can provide a more accurate understanding of contextual factors. Bodystorming sessions were found memorable and inspiring. It is best suitable for designing for activities that are accessible and unfamiliar to the researchers. 相似文献